In the past decades, a tremendous amount of research and development has been expended in the field of semiconductor circuits. Microelectronics chips made out of silicon can now be found in everything from microwave ovens to communications satellites. Advances in semiconductor technology, especially in the field of semiconductor processing, beget an emerging technology known as micro-machining or micro-electromechanics.
Micro-electromechanical systems (MEMS) are fabricated with many of the same fabrication techniques that have miniaturized electronic circuits and have made mass-production of silicon integrated-circuit chips possible. Using fabrication techniques such as wet etching and photolithography, basic structures like grooves, holes, trenches, hemispheres, cantilevers, gears, and shafts, etc., can be built on a silicon wafer. From these basic structures, a wide variety of mechanical devices can be constructed. Among the many MEMS that have been successfully implemented are valves, springs, nozzles, printer heads, accelerometers, and chemical sensors. Even a device as complex as a gas chromatograph, an instrument for identifying and quantifying the composition of gases in an unknown mixture, can now be built on a silicon wafer a few centimeters in diameter.
In such MEMS, various different electrical and mechanical devices are integrated. For instance, a power supply, a micro-motor and a chemical sensor may be constructed on a single chip. These various different electrical and mechanical devices, however, may require different voltage levels to operate. Conventionally, these different voltage levels are provided by potential dividers or transformers. However, the conventional methods for providing different voltage levels are not ideal for MEMS. For instance, potential dividers are highly dissipative and may generate excess heat undesirable in certain applications; and transformers may take up a disproportionate amount of valuable die area. More importantly, conventional voltage converters may not be fast enough for certain micro-electromechanical applications which require an ultra-fast response time.
Thus, there exists a need for a voltage shifter that is particularly compatible with micro-electromechanical systems. What is further needed is a micro-electromechanical voltage shifter that employs micro-mechanical elements to achieve voltage shifting by a combination of electrical and mechanical principles.